Hypervisors have been developed as a technology for virtualizing a computer hardware configuration by software to implement plural virtual machines in a physical computer, such that these virtual machines run in parallel using an operating system (OS) independent of the OS that operates the physical computer. Such a hypervisor creates virtual machines that each behave like computer hardware to operate various OS's on the virtual machines.
One example of a device using a hypervisor is a communication device described in Patent Literature 1. The communication device of Patent Literature 1 includes, on a hypervisor, a capture processing unit that captures communication data between virtual machines. The capture processing unit acquires communication data transferred from a first virtual machine to a second virtual machine, and stores the acquired communication data in a storage unit, thus to log the communication data.